NIELIT 2016 DEC Scientist B (IT) - Section B: 12

Question

Which of the following sorting procedures is the slowest?

• A. Quick Sort
• B. Merge Sort
• C. Shell Sort
• D. Bubble Sort

Answer 1

Option D  Bubble Sort

Time complexity of merge sort is $O(nlogn)$ in all cases best ,average, worst

time complexity of quick sort in best case $O(nlogn)$ and in worst case $O(n^{2})$

time complexity of sell sort in best case $O(nlogn)$ and in worst case $O(n^{2})$

Time complexity of Bubble sort take  $O(n^{2})$ in all case best ,average ,and worst so bubble sort is slowest in among all.

Comments

Bubble Sort takes Ω(n) in the best case. The option provided is not correct.

Ref: https://www.geeksforgeeks.org/time-complexities-of-all-sorting-algorithms/

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I guess since it is talking about the slowest algorithm, we must consider TC in worst case to benchmark the performance of the algorithm, so all the given options are right

Answer 2

Option D ) Bubble sort is slowest because , Average case complexity of bubble sort is O(n^2)

                 , Avg. case complexity of quick sort and merge sort is O(nlogn)       

                 , Avg. case complexity of shell sort is O(n^3/2)